| /* Shared library add-on to iptables to add simple non load-balancing SNAT support. */ |
| #include <stdio.h> |
| #include <netdb.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <getopt.h> |
| #include <iptables.h> |
| #include <linux/netfilter_ipv4/ip_tables.h> |
| #include <linux/netfilter/nf_nat.h> |
| /* For 64bit kernel / 32bit userspace */ |
| #include "../include/linux/netfilter_ipv4/ipt_SAME.h" |
| |
| /* Function which prints out usage message. */ |
| static void |
| help(void) |
| { |
| printf( |
| "SAME v%s options:\n" |
| " --to <ipaddr>-<ipaddr>\n" |
| " Addresses to map source to.\n" |
| " May be specified more than\n" |
| " once for multiple ranges.\n" |
| " --nodst\n" |
| " Don't use destination-ip in\n" |
| " source selection\n" |
| |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| " --random\n" |
| " Randomize source port\n" |
| #endif |
| , |
| IPTABLES_VERSION); |
| } |
| |
| static struct option opts[] = { |
| { "to", 1, 0, '1' }, |
| { "nodst", 0, 0, '2'}, |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| { "random", 0, 0, '3' }, |
| #endif |
| { 0 } |
| }; |
| |
| /* Initialize the target. */ |
| static void |
| init(struct ipt_entry_target *t, unsigned int *nfcache) |
| { |
| struct ipt_same_info *mr = (struct ipt_same_info *)t->data; |
| |
| /* Set default to 0 */ |
| mr->rangesize = 0; |
| mr->info = 0; |
| mr->ipnum = 0; |
| |
| } |
| |
| /* Parses range of IPs */ |
| static void |
| parse_to(char *arg, struct ip_nat_range *range) |
| { |
| char *dash; |
| struct in_addr *ip; |
| |
| range->flags |= IP_NAT_RANGE_MAP_IPS; |
| dash = strchr(arg, '-'); |
| |
| if (dash) |
| *dash = '\0'; |
| |
| ip = dotted_to_addr(arg); |
| if (!ip) |
| exit_error(PARAMETER_PROBLEM, "Bad IP address `%s'\n", |
| arg); |
| range->min_ip = ip->s_addr; |
| |
| if (dash) { |
| ip = dotted_to_addr(dash+1); |
| if (!ip) |
| exit_error(PARAMETER_PROBLEM, "Bad IP address `%s'\n", |
| dash+1); |
| } |
| range->max_ip = ip->s_addr; |
| if (dash) |
| if (range->min_ip > range->max_ip) |
| exit_error(PARAMETER_PROBLEM, "Bad IP range `%s-%s'\n", |
| arg, dash+1); |
| } |
| |
| #define IPT_SAME_OPT_TO 0x01 |
| #define IPT_SAME_OPT_NODST 0x02 |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| # define IPT_SAME_OPT_RANDOM 0x04 |
| #endif |
| |
| /* Function which parses command options; returns true if it |
| ate an option */ |
| static int |
| parse(int c, char **argv, int invert, unsigned int *flags, |
| const struct ipt_entry *entry, |
| struct ipt_entry_target **target) |
| { |
| struct ipt_same_info *mr |
| = (struct ipt_same_info *)(*target)->data; |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| int count; |
| #endif |
| |
| switch (c) { |
| case '1': |
| if (mr->rangesize == IPT_SAME_MAX_RANGE) |
| exit_error(PARAMETER_PROBLEM, |
| "Too many ranges specified, maximum " |
| "is %i ranges.\n", |
| IPT_SAME_MAX_RANGE); |
| if (check_inverse(optarg, &invert, NULL, 0)) |
| exit_error(PARAMETER_PROBLEM, |
| "Unexpected `!' after --to"); |
| |
| parse_to(optarg, &mr->range[mr->rangesize]); |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| if (*flags & IPT_SAME_OPT_RANDOM) |
| mr->range[mr->rangesize].flags |
| |= IP_NAT_RANGE_PROTO_RANDOM; |
| #endif |
| mr->rangesize++; |
| *flags |= IPT_SAME_OPT_TO; |
| break; |
| |
| case '2': |
| if (*flags & IPT_SAME_OPT_NODST) |
| exit_error(PARAMETER_PROBLEM, |
| "Can't specify --nodst twice"); |
| |
| mr->info |= IPT_SAME_NODST; |
| *flags |= IPT_SAME_OPT_NODST; |
| break; |
| |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| case '3': |
| *flags |= IPT_SAME_OPT_RANDOM; |
| for (count=0; count < mr->rangesize; count++) |
| mr->range[count].flags |= IP_NAT_RANGE_PROTO_RANDOM; |
| break; |
| #endif |
| default: |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* Final check; need --to. */ |
| static void final_check(unsigned int flags) |
| { |
| if (!(flags & IPT_SAME_OPT_TO)) |
| exit_error(PARAMETER_PROBLEM, |
| "SAME needs --to"); |
| } |
| |
| /* Prints out the targinfo. */ |
| static void |
| print(const struct ipt_ip *ip, |
| const struct ipt_entry_target *target, |
| int numeric) |
| { |
| int count; |
| struct ipt_same_info *mr |
| = (struct ipt_same_info *)target->data; |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| int random = 0; |
| #endif |
| |
| printf("same:"); |
| |
| for (count = 0; count < mr->rangesize; count++) { |
| struct ip_nat_range *r = &mr->range[count]; |
| struct in_addr a; |
| |
| a.s_addr = r->min_ip; |
| |
| printf("%s", addr_to_dotted(&a)); |
| a.s_addr = r->max_ip; |
| |
| if (r->min_ip == r->max_ip) |
| printf(" "); |
| else |
| printf("-%s ", addr_to_dotted(&a)); |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| if (r->flags & IP_NAT_RANGE_PROTO_RANDOM) |
| random = 1; |
| #endif |
| } |
| |
| if (mr->info & IPT_SAME_NODST) |
| printf("nodst "); |
| |
| #ifdef IP_NAT_RANGE_PROTO_RANDOM |
| if (random) |
| printf("random "); |
| #endif |
| } |
| |
| /* Saves the union ipt_targinfo in parsable form to stdout. */ |
| static void |
| save(const struct ipt_ip *ip, const struct ipt_entry_target *target) |
| { |
| int count; |
| struct ipt_same_info *mr |
| = (struct ipt_same_info *)target->data; |
| |
| for (count = 0; count < mr->rangesize; count++) { |
| struct ip_nat_range *r = &mr->range[count]; |
| struct in_addr a; |
| |
| a.s_addr = r->min_ip; |
| printf("--to %s", addr_to_dotted(&a)); |
| a.s_addr = r->max_ip; |
| |
| if (r->min_ip == r->max_ip) |
| printf(" "); |
| else |
| printf("-%s ", addr_to_dotted(&a)); |
| } |
| |
| if (mr->info & IPT_SAME_NODST) |
| printf("--nodst "); |
| } |
| |
| static struct iptables_target same = { |
| .next = NULL, |
| .name = "SAME", |
| .version = IPTABLES_VERSION, |
| .size = IPT_ALIGN(sizeof(struct ipt_same_info)), |
| .userspacesize = IPT_ALIGN(sizeof(struct ipt_same_info)), |
| .help = &help, |
| .init = &init, |
| .parse = &parse, |
| .final_check = &final_check, |
| .print = &print, |
| .save = &save, |
| .extra_opts = opts |
| }; |
| |
| void _init(void) |
| { |
| register_target(&same); |
| } |